Fire control



Feb. 8, 1949. H. K. wElss 2,460,863

FIRE CONTROL Filed July 10,(1943` TBGET TEQCKEB wwmom Herbert K -Wei mcammmw Patented Feb. 8, 1949 UNITED STATES PATENT GFFCE 9 Claims.

(.Grented under the act of Merch. 3,. 1.883,. as..

amended April 3.0.1928; 37.0 0. G.. 75T) controlt dir@eters or oomeuters.. Sue-1,1. directors are.. used? prineieaiiv in dries on .moving targets oomgtise means. for; setting; in values of range, esteoiieneoiis. angular @edition relatively t0 predetermined; bese lines or; the line- 'between direcgetLetrldg.y the; component angular. rates' moves.: about. predetermined. axes limelight the director position. These4 values: elio them combined. by the director and output. Welnee Qt the `correct; trein; and elevationy enigles for the are. oontinuoiisltg siienliedy thereby. The aforesaid e geler. retos ereY usually. taken .he eboutiverticel: and horizontal axes.. Qi the. line fromtiie; directory to.. the 4target ets-l dete mined by sound lote-tors siehts, or reader.. Tzhe. device for: determininefi the instentame-ousvv ofthe line between.l director andY tere-et isf mei-.firmly controlledend. subject to smell. unevoi-delble eli-,ratio operation on thepart. of the et. whlo Op lith introduites so.-celled tracking er- Since; e smooth tracking rete. is essen;

el? to setisieotoryoeeretion. oiw the-director` it isf customary to; provide; al smoothing device-v inter eeseflfbetween the dritte fr-omthe tracking-Einemben, Vizi, thel sight; soilnd locator yori-radar, to the corresponding; iutthef director.

Lt is.` thesobj .ect-.ofi this invention.: to devisenew meanshaivine? peculiar advantages for. smoothing out; thesel perturbatidlls, ,leavingA theitindemen-tetl rate-.fthet of the.- terget without. theA perturbar. tionsfeto.- be passed. olito; the.; ored-ictor or directoofor. prediction. Eon-this.eunposelheveshown two.embodime11.td0.myg invention in the aooomterminer dimi/ings, wherein.;

Fis. 11 is dia-ere@metioillusttotiodo.asimple. slngle-.stagofslmoath and Eigf. 2.1 isV a., dieerrmmatio iliilstreton. ofE e. two stage smoother;

A; onstently. operating; constant. speedmotor lo ives,` thriongiiltbebcveligeors. 2.9. shown inVx sie. ttheveridblesneed diiv *.Qglli more par. tioiilanly.; the eongstfantsnee dise 9, thereof. The outputfsheft otlie v iebieseeeddriy'e-Q, 1., il,` on whieh. the c flszlilider;v 8@ ofg'tlief driveis secured, is: connected. by bevel, gears.. 3v2gto the; smoothed. rate shaft.. 2 wligln is..-oo.nriee ted. as; tile. inputv to. the dineemt.` or` lorodieser (not shown. Smoothed-r reteY she-ft: 2.. is. connected. totherient 'ng devices used principally in gun lire h: aseeria/l'. sanitarie ships and, in generell..A

bevel. ygear oi e, dierentiol 3. the. left. coaxial' bevel. gear of which is secured: on. the. trackme rete shaft. l. comingV from the tracking4 de vioe (not shown.).. By. means of.' differential' 3l,A the rete from the.- Verieble, speed drive. 1, 8T.. as, applied to smoothed rate shaft. 2,- is. matched With the rate.. from the tracker.. as applied to trackingy rete shaitA l.. Fig,4 1 represents. the improved smoothing. device ot; this.. inyention. In.. the ordinary smoothing devise.. the. third. shaft off. the. diierentiel 3. would, be. connected diireotly. to. thesbell` cage '1, (i. e.,4 tofrod. 21 supportbellcaee il) of. theimriocble sneed. drive s, 1;I 8.., The; next tewremiarks refer. to the ordinary. smoothing. device.. and. not. to, the. improved*y smoothing. device of this. invention. If, rates ot. motion ofshafts.; i and 2. are. noteqiieh the dif'- ference isY obtained. by. difierentiel. 3. and" applied through. intermediate mechanisms. to, neposition bell. carriage l.. invv a. direction tiomore. nearly,

equalize the. rates., Because4 the. bell cage. does..

not respond. instantly., there. ish a. lag in the rate matching oneration whioh. tends, to smooth the rate L It. een.. be. shown. easily by mathematics f that the.A slower; the. ball, coge 1 responds to a.

change in. nateon. shaft.. L, thebetter. itA Willi smooth af. kperturbetion superimposed on. the. basic rate ot shaft l, but, also, that` the. time r-.eqiiilled t0: rea-ch. e.: measurement of thsbeslerate iromany other. measurement. ofi ai preyious. rate (this. isy

comamolfrlyA known. as. the settling time of" the..

smoothemf will.. be correspondingly lengthened. The term diieltential as used. in this specilicetionis. specifically. applied'. to a. common fonm Qigear. train in; which threememhers are, representedv by.- -two. coaxial s un. gears.. and a... third Y coaesiel..Y ring gear member.r having plane-tary pinion.V

geovs revoliibly mounted. thercwithin. meshed' with thetwo first namedv soestotransmit torque .once from. on toy the. third member equally. fowevcre they term is. notlim-ited tothis exact form. of.I gearing and isintendedtoinolude equivalents.

It..11o1lows. that, in. smoothers. of" pest... design, a. oom-eromise mustbe struck` between settling. time.J and smoothing abilitynior` lfj smoothingV was. hea-Vy.; the time required to. settle to adequate date.- would. be exoessiveandwth quick settling.Y timeI little, smoothing oo uldl` be obtained:

By..pxoviding.@.variatbletime constant; however; the question. of. ex-cessillefsettling. time is elimih noted. and entfl desired amount of' smoothingl oemY be obtained with. thei smoothing; system. 011ev method of. accon'iplishingi this variable timeoon- .st-ont. (there, are others., and-1 it isnot the intent of this description to limit the application to the particular method here described) is by interposing a small variable speed device as, for instance, at 4, 5, E :between differential 3 and ball cage 1, so that it is possible, by changing the position of ball cage 5 of the small variable speed drive, to change the degree which a given movement of output from differential 3 will cause the ball cage 1 o-f the main variable speed drive to be displaced, thereby changing the time -constant, and the settling time of the smoother.

As mentioned above, in the ordinary smoother, the output shaft 33 of the differential 3 would be connected directly to the rod 21 to which the ball cage 'l of the variable speed drive 9, 1, 8 is attached. However, in the improved smoother of this invention, the shaft 33 is connected to the rod 21 through a second variable speed drive 4, 5,

6, the input disc 4 of which is secured to shaft 33 and output cylinder E of which is connected to the rod 21 through pinion and rack 26. The position of ball cage 5 may optionally be varied at any predetermined time to progressively change the time constant and the settling time of the smoother, in a manner to be described. Ball cage 5- is secured at one end of a rod I5, the other end of which is maintained in contact with edge cam i4 by compression spring I6. Cam I4 is secured on ay shaft 34 which is driven at times through bevel gears 25 and a clutch II from the left gear of the aforedescri-bed bevel Igear drive 29 of the constant speed motor I0. Coil, torque spring I3 associated with cam shaft 34 serves to return cam I4 and ball cage 5 to their starting positions Whenever the connection from cam to motor I0 is broken; clutch II controlled externally Iby knob I2 being a possible method of coupling and uncoupling the motor drive to and from the cam I4 and the ball cage 5. The motor drive operates to move the ball cage 5 from its outermost position when the time constant of the smoother is short to a position close -to the center, perhaps even at the center of the small variable speed drive, Where the time constant of the smoother becomes large.

The tracker picks up target as usual, and a rate, perturbed |by errors appears on shaft I. The smoother, having at this stage a very short time constant, quickly matches the rate, settling in a very few seconds, but doing little smoothing. When input data seems good (as would be indicated if @operation continues a short time without indication of abrupt chan-ge of rate), the operator by operating knob I2 closes clutch II, which by allowing the motor I3 to drive ball cage 5 from cam I4 causes the time constant of the smoothergradually to lengthen, attenuating more and more the perturbation of the rate received from the tracker. Finally, if the ball cage 5 is allowed to reach and remain at the center of disc 4- the output rate on shaft 2 is constant and is affected no more by perturbations of input.

' The effect is that of beginning to track with a director no worse than a present standard director with no smoothing, but of having output data improve with tracking time, until if the target has iiown' a straight line, constant speed course, the rate determination will eventually be as perfeet as the mechanical accuracies of the director allow. No penalty is paid for heavy smoothing in the form of long settling time as in smoothers heretofore used where no usable data at all was obtained until the smoothing circuit was settled. Hence, all courses, however short, can be red upon with output data improving directly with tracking time.

For surveillance of the solution after ball cage 5 has reached the center of disc 4, a dial I1 is geared to the output shaft 33 of differential 3, which indicates the difference between the input rate land the smoothed rate 2. It should be understood that with the device constructed as in Fig. 1, and without the use of the cam I4, the initial positions of the parts would be with the cage 1 on the axis of disc 9 and therefore inoperative to transmit motion through the cylinder 8 to sha-ft 2, and the cage 5 of the first variable speed device would be as shown, the shafts I, 2 and 33 being stationary. In this condition, if any lmotion is imparted to tracking rate shaft I, in either direction, as would occur in the beginning of an encounter with a moving Iairplane target (the immediate results of which movement, if incident to bringing a telescope sight into first bearing on the target may be disregarded), motion is transmitted through shaft I to the first differential. If the movement so transmitted is clockwise resulting from right traverse, motie-n of the shaft 2 being opposed by the zero position of the cage 1, the pinions of the differential 3 will travel on the right coaxial gear, carrying the ring gear clockwise at double the speed of shaft I and operating the third shaft 33, dial I1, and input disc 4, of the first variable speed drive. The resultant motion of the cylinder 5 raises the cage 1. This gradually begins and increases the rate of movement of the shaft 2 in a direction the opposite of that of shaft I, until the speed of the latter is matched in shaft 2. At this stage, there being no difference in rate between shafts I and 2, motion of the ring gear' of the first differential ceases, and the dial I1 and parts 4, 5, 5 likewise become still. This 40 holds the cage 1 at the position which effected the matching of motions of shafts 2 and I, and the shaft 2 is then being operated by the motor I0 without aid from shaft I. The latter is also being operated in the direction and speed as manually developed, due to the ring gear of the first differential serving as a stationary support for the planetary pinions, so that they transmit reverse motion of the right hand concentric gear to the left one. The gun crew tracker or other tracker operating the manual mechanism keeps his hand on and moving with the crank or the like, although propulsion thereof may not be required. Should movement of the target or error in preceding manipulation involve need for increased rate of movement of the tracker shaft I, the operato-r applies force enough to increase the rate in this shaft. For the moment the shaft 2 is under operation by motor IB of the previously set rate, and the motor opposes increase thereof. In consequence the Ipinions of the first differential travel somewhat faster on the right gear and acquire a translative or planetary movement by which motion through the ring gear, and shaft 33 is transmitted to Ithe dial l1 and disc 4, resulting in a still further lift of the ball cage 1 with consequent increasedA speed transmitted to shaft2, until motion Aof sha-ft I is Vagain matched and dial l1 and disc 4 become stationary. Should the imposed rate of shaft 2 be too high, the operator retards the motion of the shaft I so that this time the predominant motion in shaft 2 being in a reverse direction, the planetary motion of the pinions is the reverse of that of the shaft l, and the shaft 33 and disc 4 are likewise moved in a direction the reverse of that first applied, .a1-

to the motor, the output member of the second variable speed drive being connected to drive the said smoothed rate shaft, the ball cage of said second variable speed drive being connected for operation by the said output member of the first said variable speed drive, and means to engage said releasable connection to cause the cam to be,

turned from its said normal position and move the said ball cage of the first variable speed drive from its said normal position toward the center of the disc, whereby the rst said variable speed drive transmits motion to adjust said second variable speed drive at a progressively decreasing rate whereby said second variable speed drive operates said smoothed rate shaft at a rate proportionate to a mean of the rates of the output shaft, with diminished fluctuations proportionate to the rate differences between the input and output shafts and the time the motor is connected to the cam.

2. In a smoothing device connected to the output tracking rate shaft of a tracking device and the smoothed rate input shaft of a director, the combination of a differential gearing connected between the said shafts and having a third shaft, a variable speed drive having an input member connected to the third shaft an output member and a movable rate-changer connected between the input and output members, a constant speed motor, a cam connected to the rate changer, the said cam being loaded to tend to assume a normal initial position such that the rate changer is at its maximum rate output position, whereby maximurn motion is transmitted initially between the input and output members of the said variable speed drive, a second similar variable speed drive` the input member of which is connected to said motor, its output member connected to the said smoothed rate shaft, and its rate changer connected to the said output member of the first variable speed drive, and releasable means to operatively connect the motor and cam to turn" the cam from its normal position and move the said rate changer of the first variable speed drive away from its normal position whereby the first said variable speedvdrive transmits motion at a progressively decreasing rate to its output member.

3. In a smoothing device connected to a tracking rate output shaft of a tracking device and the smoothed rate input shaft of a director, the combination of a differential gearing connected between the said shafts having a third shaft, a constant speed motor, a cam loaded toward a normal initial position, a clutch connection therefrom to the motor, a variable speed drive having an input member connected to the said third shaft and having a speed control, a follower on the said cam operatively connected to said speed control of said variable speed drive so that the latter is normally at its maximum rate output position, a second similar variable speed drive the output member of the first variable speed drive being connected to the speed control of the second variable speed drive, the output member of the second variable speed drive connected to the smoothed rate shaft and means for closing the said clutch to cause the cam to be turned from its said normal position to move the speed control of the first variable speed drive so as to transmit motion at a progressively decreasing rate depending upon the rate difference between the tracking rate shaft and the smoothed rate shaft, to the speed control of said second variable speed drive and so that the latter will drive the smoothed rate shaft at a rate depending both upon the rate difference between the tracking and smoothed rate shafts and upon the time that the clutch remains closed.

4. In a smoothing device connected between a tracking rate outputV shaft of a tracking device and thesrnoothed rate input shaft lof a director, the combination of a differential gearing connected to the tracking rate shaft and the smoothed rate shaft and having a third element, a, variable speed drive operatively connected to the said third element, a second variable speed drive operatively connected between the first variable speed drive and the smoothed rate shaft,

- and means operable over variable time periods` toA control Athe first variable speed drive to transmit motion at a progressively decreasing rate to the smoothed rate shaft. Y

5. In a smoothing device adapted to be connected to a tracking rate output shaft of a tracking device and a smoothed rate input shaft of a director, the combination of a differential gearing connected between the tracking rate shaft and the smoothed rate shaft and having a third shaft, a variable speed drive having an input disc connected to the third shaft and having an output member and an interposed changeable connector, a cam connected to said changeable connector, the said cam being loaded toward a normal position, the normal position of the cam and the connected changeable connector being such thatr the latter is normally disposed eccentrically on the discwhereby a maximum motion is initially'transmittable between the said input disc and the output member of the variable speed drive, a second similar variable speed drive, a constant speed motor connected to the input disc thereof, the variable connector of the second variable speed drive connected to the said output member of the first variable speed drive, a third similar variable speed drive, the output member thereof connected to the said smoothed rate shaft and the input disc thereof operatively connected to said constant speed motor, a second differential gearing connected between the output member of the second variable speed drive and the changeable connector of the third variable speed drive, the third shaft of the second differential being connected to the said output member of the first mentioned variable speed drive, a means to at will connect thesaid cam and motor to turn the cam from its said normal position to progressively move the said changeable connector of the first variable speed drive from its said normal position whereby the first variable speed drive transmits progressively decreasing motion resultant upon the rate difference between the tracking rate shaft and the smoothed rate shaft, a third differential included in the smoothed rate shaft, and means to yieldingly oppose rotation of the third shaft of the third differential.

6. In a smoothing device adapted to be connected to a tracking rate output shaft of a tracking device and a smoothed rate input shaft of a director, the combination of a differential gearing connected between the `trackingr rate shaft and the smoothed rate shaft and having a third shaft, a variable speed drive having an input disc connected to the third shaft and having an output member and an interposed changeable connector, a cam connected to said changeable connector, the said cam being loaded toward a normal position, the normal position of the cam and the connected changeable connector being such that the latter is normally disposed eccentrically on the disc whereby a maximum motion is initially transmittable between the said input disc and the output member of the variable speed drive, a second similar variable speed drive, a constant speed motor connected to the input disc thereof, the variable -connector of the second variable speed drive connected to the said output member` of the rst variable speed drive, a third similar variable speed drive, the output member thereof connected to thesaid smoothed rate shaft and the input disc thereof operatively connected to said constant speed motor, a second differential gearing connected between the output member of the second variable speed drive and the changeable connector of the third variable speed drive, the third shaft of the second differential being connected to the said output member of the iirst mentioned variable speed drive, a means to at will connect the same cam and motor to turn the cam from its said normal position to progressively move the said changeable connector of the iirst variable speed drive from its said normal position whereby the rst variable speed drive transmits progressively decreasing motion resultant upon the rate difference between the tracking rate shaft and the smoothed rate shaft, a third differential included in the smoothed rate shaft, a heart-shaped cam, a fourth differential connected between the said cam and the third shaft of the third dilerential, a spring-pressed detent normally engageable in the notch of the said heart-cam, spring means connected to and urging the cam toward normal position, a stop motion for the last named shaft, a driving connection between the third output shaft of the rst differential and the third shaft of the fourth differential whereby the heart-cam, is turned away from its said normal position, and means to disengage the stop motion.

7. In a rate smoother, an input member, an output member,v a iirst variable speed device, means driving said device by and in proportion to any difference in rates between said members, a second variable speed device, a driving connection between the output of said second variable speed device and said output member, means operable to vary the speed ratio of said second variable speed drive by and in response to the 10 output of said first variable speed drive, and manually controlled means operable to vary the speed ratio of said rst variable speed drive.

8. In a rate smoothing device, an input shaft, an output shaft, a diierential having rst and second sides connected to said shafts, respectively, rst and second variable speed drives, means driving said first variable speed drive from the third side of said dilferential, means drivingly connecting the output of said first variable speed drive to vary the speed ratio of said second variable speed drive, power means driving said second variable speed drive, a driving connection between the output of said second variable speed drive and said output shaft, and manually-controlled means operable to vary the speed ratio oi said rst variable speed drive.

9. In a rate smoother, an input member, an output member, a rst differential connecting said members, a rst variable speed device having an input driven by said rst diierential in proportion to the diierence in rates of movement of said members, a second variable speed device having its output connected to drive said output member,

REFERENCES CITED The following references are of record in the l file of this patent:

UNITED STATES PATENTS 

